iOS - 6.19.0 release bundle is missing env vars from react-native-dotenv

[jamesholcomb]

What React Native libraries do you use?

RN New Architecture, Hermes, React Navigation

Are you using sentry.io or on-premise?

sentry.io (SaS)

@sentry/react-native SDK Version

6.19.0

How does your development environment look like?

⬇  Place the `npx react-native@latest info` output here. ⬇

info Fetching system and libraries information...
System:
  OS: macOS 15.6
  CPU: (10) arm64 Apple M1 Max
  Memory: 130.27 MB / 32.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 22.17.0
    path: ~/.nvm/versions/node/v22.17.0/bin/node
  Yarn:
    version: 3.8.3
    path: ~/.nvm/versions/node/v22.17.0/bin/yarn
  npm:
    version: 10.9.2
    path: ~/.nvm/versions/node/v22.17.0/bin/npm
  Watchman:
    version: 2025.06.23.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /opt/homebrew/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 24.5
      - iOS 18.5
      - macOS 15.5
      - tvOS 18.5
      - visionOS 2.5
      - watchOS 11.5
  Android SDK: Not Found
IDEs:
  Android Studio: 2024.3 AI-243.24978.46.2431.13208083
  Xcode:
    version: 16.4/16F6
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.11
    path: /usr/bin/javac
  Ruby:
    version: 2.7.7
    path: /Users/jamesholcomb/.rbenv/shims/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 18.0.0
    wanted: 18.0.0
  react:
    installed: 19.0.0
    wanted: 19.0.0
  react-native:
    installed: 0.79.4
    wanted: 0.79.4
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: true

Sentry.init()

  const opts: Sentry.ReactNativeOptions = {
    dsn: __DEV__ ? undefined : SENTRY_URL,
    // Sentry uses {bundleid}-{version} for release names
    // https://github.com/getsentry/react-native-sentry/issues/516
    release: `${DeviceInfo.getBundleId()}@${DeviceInfo.getVersion()}+${DeviceInfo.getBuildNumber()}`,
    dist: DeviceInfo.getBuildNumber(),
    environment: __DEV__ ? "development" : new URL(SERVER_URL).hostname,
    enableNative: true,
    enableNativeCrashHandling: true,
    integrations: __DEV__
      ? []
      : [
          Sentry.breadcrumbsIntegration({
            console: true
          })
        ],
    beforeBreadcrumb(breadcrumb) {
      if (breadcrumb.category === "console") {
        if (breadcrumb.level === "debug" && !consoleDebugBreadcrumbs) {
          return null
        }
        // sentry does a poor job of serializing console logs, do it here
        breadcrumb.message = JSON.stringify(breadcrumb.data.arguments)
      }

      return breadcrumb
    },
    maxBreadcrumbs: 50
  }

  Sentry.init(opts)

Steps to Reproduce

On iOS only, after upgrading from react-native-sentry 6.15.0 to 6.19.0, the main.jsbundle output is missing the transformation applied by the react-native-dotenv plugin. According to the log, it occurs after the xcode "Bundle React Native code and images" phase has completed (I use the recommended docs value for that).

I can confirm that react-native-dotenv is transforming the output correctly (and this worked fine in 6.15.0).

metro.config.js

// @ts-check
/* eslint-disable @typescript-eslint/no-require-imports */
const { getDefaultConfig, mergeConfig } = require("@react-native/metro-config")
const {
  wrapWithReanimatedMetroConfig
} = require("react-native-reanimated/metro-config")
const { withSentryConfig } = require("@sentry/react-native/metro")
const path = require("path")
const defaultConfig = getDefaultConfig(__dirname)
const { assetExts, sourceExts } = defaultConfig.resolver

/**
 * Metro configuration
 * https://facebook.github.io/metro/docs/configuration
 *
 * @type {import('@react-native/metro-config').MetroConfig}
 */
const config = {
  cacheVersion: process.env.APP_ENV,
  transformer: {
    babelTransformerPath: require.resolve("react-native-svg-transformer")
  },
  resolver: {
    extraNodeModules: {
      "~": path.resolve(__dirname, "src")
    },
    assetExts: assetExts.filter((ext) => ext !== "svg"),
    sourceExts: [...sourceExts, "svg"]
  }
}

const baseConfig = mergeConfig(defaultConfig, config)

module.exports = withSentryConfig(wrapWithReanimatedMetroConfig(baseConfig))

Expected Result

The output bundle contains the transformed output from react-native-dotenv plugin.

Actual Result

The output bundle is missing the dotenv env vars from the plugin.

[linear]

RN-301 iOS - 6.19.0 release bundle is missing env vars from react-nantive-dotenv

[kahest]

Thanks @jamesholcomb for the details, we'll investigate and follow up here

[alwx]

@jamesholcomb
I've investigated this issue, and the seems like it cannot be reproduced anymore with the current version of sentry-react-native. It might be related to some changes in React Native itself or changes in Metro but I don't think we did anything that might affect how transformation is done between 6.15 and 6.19 since there was only one tiny change to our build scripts done during this period, and it's unlikely this change broke things for you. However, we bumped several dependencies, and those dependencies might've led to the results you've got.

Either way, I recommend updating sentry-react-native to 7.3+ because that will probably resolve the issue — I've set up a test project and made sure react-native-dotenv 3.4.11 and sentry-react-native 7.3.0 work fine together.

I hope it helps.